A nozzle-type electron beam irradiation device provided in electron beam sterilization equipment emits an electron beam from a vacuum nozzle of the sterilization equipment and thus an electron beam can be emitted to the inner surface of a sterilization object such as a container from the tip of the vacuum nozzle inserted from the mouth of the container. In other words, in such electron beam sterilization equipment, the inner surface of a container is sterilized by direct irradiation with an electron beam from a nozzle-type electron beam irradiation device, thereby suppressing the intensity of the emitted electron beam. Thus, the electron beam sterilization equipment can reduce power consumption and suppress the irradiation of a strong electron beam so as to reduce the deterioration of the container, as compared with equipment for sterilizing the inner surface of a container by irradiation with a strong electron beam from the outside of the container.
In an electron beam irradiation device such as a nozzle-type electron beam irradiation device, the inside of a vacuum chamber needs to be placed in a high-vacuum atmosphere by a high-vacuum pump in order to accelerate an electron beam emitted from the source of the electron beam. In this case, the source of the electron beam also generates gas with heat for generating the electron beam and thus the high-vacuum pump is preferably disposed near the source of the electron beam. According to the related art, a device with a high-vacuum pump (specifically, an ion pump) disposed near the source of an electron beam is proposed (for example, see Patent Literature 1).